your Read command is not correct, as you have forgotten to include the parity bit. the number of 1's in the SPI message must always be odd. your SPI command of 0x8008 0000 contains an even number of bits,and so the part will reject this command as an error. it will give you an error response instead of the data you want.

the correct command would be: 0x8008 0001

this command properly implements the parity bit to ensure that an odd number of bits exist in the command.

your Read command is not correct, as you have forgotten to include the parity bit. the number of 1's in the SPI message must always be odd. your SPI command of 0x8008 0000 contains an even number of bits,and so the part will reject this command as an error. it will give you an error response instead of the data you want.

the correct command would be: 0x8008 0001

this command properly implements the parity bit to ensure that an odd number of bits exist in the command.

i can confirm that the ADXRS450 device will transmit 0x00000001 as the first SPI response after power has been applied. if you are not witnessing this response, then i would recommend to connect an oscilloscope to the SPI signals (especially /CS), and monitor them from the moment that power is applied to your system. as you are using a GPIO pin for the component chip select, the initialization process of the micro-controller may toggle the states of these signals and cause SPI errors that you are unaware of.

the response 0x5E0A 4040 is not actually nonsense. this is a valid response for a read command. the first byte of the response "0x5E" immediately reveals that the message is a response to a read command issued by the Master Device. this response format can only be given if you have transmitted a valid read request to the device, so somewhere in your code you have attempted to read a register. It's not possible for this to be the first response (0x0000 0001) from the device as you must have previously sent a read command in order to get a response formatted in this way.